Best Way to Heat a Car Wash for Freeze Protection
The car wash industry is booming these days, from drive thru gas station washes to multi-million dollar facilities that offer monthly subscriptions for unlimited washes. In parts of the country that get below freezing temperatures in the winter, a car wash manager must have a solution for freeze protection. If the wet brushes freeze they will no longer work. Vehicles can lose control when the entrance or exit are iced over. Great Lakes Radiant offers the #1 carwash heater by Re-Verber-Ray – a fully stainless steel radiant tube heater that offers the best efficiency for freeze protection.
Hot Air vs Radiant Heat
Car wash tunnels typically experience a lot of air flow, especially when a car enters and exits the wash. Most car washes have garage style doors at the entrance and exit. If you try to heat the space with hot air (unit heater, makeup air unit, etc), when the doors open the hot air simply escapes. The hot air units then must go into full blast mode to recover and get back to the thermostat setpoint.
With radiant heat warming the concrete floor and objects in the car wash, there is much less heat loss when the doors open. The concrete absorbs a massive amount of heat and re-radiates the heat back up like a blacktop parking lot on a hot day. Instead of using newly combusted hot air to recover, you are using the existing heat that has been absorbed into the floor and objects. Radiant heaters will still kick on to recover, but the recovery is much more manageable from an efficiency standpoint.
The Car Wash
You won’t need a lot of heat to achieve freeze protection in a car wash tunnel. Set the thermostat just above freezing (35-40 degrees). Car wash tunnels are long and radiant tube heaters are perfect for covering a lot of space since these units can get up to 70’ in length. Our DX2 and HL2 Series heaters come standard with a stainless steel burner box, with optional upgrades to stainless steel tubes, reflectors, and hardware. These units are made with corrosion resistant material to prevent damage from harsh chemicals.
The equipment room is often a separate concern that we can tackle. These small rooms have a variety of equipment that also needs freeze protection. There are no harsh chemicals or water flying around in these rooms, so stainless steel units are not needed. We typically use the DR Series for equipment rooms, and recommend installing a small louver to allow the exhaust gasses to escape. We also recommend going with the millivolt units because they don’t require power to the unit. Milivolt units will still heat the space even if the power goes out.
Clearances to Combustibles
The biggest design consideration we see is with “clearances to combustibles.” Combustible items include the car wash brushes, hoses that connect to the equipment, anything made of wood or rubber, and any other items that could catch fire or melt. These “clearances to combustibles” are distances in inches that you must be away from a combustible item. For example, typical top clearances range from 6-8 inches. The bottom clearances are always the largest, since that is where the heat shines down. Here is an example of typical clearances:
Heater Sizing and Quantity
Lower BTU units are ideal for these applications because they are only serving as freeze protection. We recommend low BTU units that cover a long distance (40’ long units are common, for example). If you have a 100’ long tunnel, a couple 40’ long units will work perfectly. Here is a typical car wash design:
We usually try to tuck a radiant tube heater up against a wall, angling the heat at 45 degrees to shine towards the center of the room. Car washes are usually packed tight, so the higher the ceiling the better. Here is an example of tucking a heater against a wall and as high as possible:
Intake & Exhaust
The harsh environment of car washes means we must pipe in fresh air from outside to go into the burner box. You don’t want the burner box to be sucking in harsh chemicals and water, right? Fresh air can be piped in very easily using PVC or metal 4” pipe. Clients prefer to use sidewall penetrations instead of roof, because roof penetrations tend to leak over time and require repair. The fresh air ensures the air flowing through the burner box is clean, and increases the life of the heater!
We also recommend getting the exhaust gasses outside by using a sidewall or rooftop exhaust kit. This requires a 4” penetration and acts as insurance that the tunnel won’t fill with exhaust gasses and cause a dangerous situation.
Strategic Use for Max Efficiency
Simply set the thermostat to the lowest possible temperature to prevent freeze protection. 35-40 degrees is usually sufficient. You may have a learning curve to nail down the perfect temperature setpoint.
Infrared radiant heat is truly the best option for protecting a car wash in freezing temperatures. Not only are the efficient, but the recommended units are built to last with stainless steel. The Re-Verber-Ray line is manufactured in Detroit, MI, and these American made systems have been recognized as the best in the industry. At Great Lakes Radiant, we are ready to assist with designing a system to heat your car wash effectively. Give us a call at 888-501-0252, or send an email to [email protected] for more information.